Computer is commonly known at the modern age. It is impossible to overestimate the importance of computers. The popularization of computers in a country often expresses the technological development of this country. Peripheral devices of a computer such as monitor and speaker are essential parts of the computer to perform multimedia effect. Accordingly, there is a great demand for interface cards, e.g. display card or sound blaster card to communicate the computer with its peripheral devices. It is a burning question for the manufacturers of interface cards how to increase testing speed and decrease testing cost.
For instance, please refer to FIG. 1 showing how to test a 3D display card. For testing the 3D display card 13, the testing system includes a computer 11 and a monitor 12. At first, the tester inserts the 3D display card 13 onto a slot of the main board 111 of the computer 11. The main board 111 will execute a basic input/output system (BIOS) program after starting the computer 11. The basic input/output system program is used for self-testing and detecting the peripheral devices electrically connected to the computer. After the computer passes the self-test predetermined by the basic input/output system program, the boot program and operating system (Dos or Windows 95) stored in the hard disk 112 are loaded in the memory of the computer 11. Then, the tester inputs an instruction for the computer to execute a test program stored in the hard disk 112 to test the 3D display card 13. The tester may watch out for the testing result from the monitor 12. The tester must turn off the computer if he wants to test another 3D display card. After a 3D display card 13 is completely tested, the tester will withdraw the tested 3D display card 13 from the slot of the main board 111 and insert another 3D display card to be tested onto the slot of the computer 11. Then, another testing procedure including starting the computer, executing the basic input/output system program, loading the operating system, and executing the testing program is repeated to test the second 3D display card.
The conventional testing procedure for testing a 3D display card is shown in FIG. 2. It includes the following steps:
step (1): adjusting the clock of video memory of the 3D display card 13 as indicated in block 21. This step is used to decrease the noises which will seriously affect the testing result. PA0 step (2): testing the video memory of the 3D display card as indicated in block 22. PA0 step (3): testing the 2D engine of the 3D display card as indicated in block 23. PA0 step (4): testing the 3D engine of the 3D display card as indicated in block 24. PA0 step (5): restoring the original clock for the video memory as indicated in block 25. PA0 step (6): testing the register group of the 3D display card as indicated in block 26. This step is used to check the register index. PA0 step (7): testing the display mode of the 3D display card as indicated in block 27. Different refresh rates are used in response to different display modes to test the display states. PA0 Step (8): showing the testing report as indicated in block 28.
However, the aforementioned testing method using the testing program stored in the hard disk is not practicable. Each testing cycle, including steps of switching on the computer, loading the operating system such as Windows 95, and completely testing the 3D display card, spends much time. The total spent time approximates 90 seconds. The testing period is so long to seriously affect the productivity. Another drawback of the conventional testing method is the damage of the hard disk caused by frequent switch. The switch between on-state and off-state with considerable frequency will result in a reduced lifetime of the hard disk. The average market cost of a hard disk is about NT$ 4,000. A hard disk can only perform 5,000 to 10,000 testing cycles. Hence, the production cost of 3D display cards can not be lowered.
Another testing system for testing a 3D display card is developed to solve the aforementioned problem. Please refer to FIG. 3 which shows another conventional testing system for testing a 3D display card. The hard disk is replaced by a read-only memory (ROM) card 312. The testing system includes a computer 31 and a monitor 32. The testing method is similar to the aforementioned one. The tester inserts the 3D display card 33 onto a slot of the main board 311 of the computer 31. The main board 311 executes the basic input/output system program after starting the computer 31. When the 3D display card 33 is detected, the testing program recorded in the read-only memory card 312 gains the master control over other programs. The testing program is executed to test the 3D display card 33. The testing result is also shown on the monitor 32. Then, the entire testing method is repeated to test other 3D display cards.
Such testing method can speed up the testing procedure because testing the 3D display card need not load the operating system. The average cost of a read-only memory card is about NT$ 100. The card employs an electrically erasable programmable read-only memory (EEPROM) which is rewritable and serviceable. Therefore, the production cost including testing cost is lowered. However, the capacity of the read-only memory card is much less than that of the hard disk. Some big testing programs can not be stored in the read-only memory card. For example, a 3D pattern used for testing the 3D engine is too big to be stored in the read-only memory card. Hence, the testing procedure can not be completed by just using the read-only memory card. It will affect the yield of the 3D display cards.